Please define "high power" and "low power". I vaguely recall some really low pressure/velocity/light bullet gallery ammunition used at one time by the Bundeswehr that I expect required manual operation of the bolt on the G1 and G3. If you're just referring to bullet weight, I'm not terribly familiar with the AR10/M&P10. A better way to take care of your functioning issue might have been a lighter/shorter recoil spring and/or a lighter buffer (if available). You'd have to change them to shoot the different types of ammunition but it'd been a much less of a potential problem.

Now, if you have your gas system set to function the rifle when using low pressure ammunition and then shoot high pressure ammunition without changing the gas adjustment you won't harm your barrel (except for possible excessive wear/cracks on the barrel extension locking lugs, but that may be available as a separate part). You will however, probably (rather depends upon the difference in chamber pressures) severely batter your bolt/bolt carrier/buffer due to higher than design specification bolt carrier velocity. The bolt will also be unlocking earlier at higher than than design spec chamber pressures and this will increase wear on the cam pin and bolt/bolt carrier. Expect cracked bolt body/locking lugs. We see those bolt problems on extensively used AR15 pattern rifles with standard ammunition in heavy use.

Hopefully, Odin included instructions on how to properly adjust the gas system. Writing down the adjustments (from fully closed) for both loads would be a good idea. Change adjustments as required.